Epulo R.A.& , 2004
Holotype species: Epulo multipedes R.A.Townsend & Huisman
Original publication and holotype designation: Townsend, R.A. & Huisman, J.M. (2004). Epulo multipedes gen. et sp. nov. (Corallinaceae, Rhodophyta), a coralline parasite from Australia. Phycologia 43: 288-295.
Precise date of publication28 May 2004 (stated at top of first page of article). The requirements for valid publication are specified in the ICBN (International Code of Botanical Nomenclature).
Taxonomic status: currently recognized as a distinct genus.
Most recent taxonomic treatment adopted: Schneider, C.W. & Wynne, M.J. (2007). A synoptic review of the classification of red algal genera a half a century after Kylin's "Die Gattungen der Rhodophyceen". Botanica Marina 50: 197-249.
Description: Plants calcified (but see comments), lacking genicula, composed largely of unconsolidated filaments but becoming pseudoparenchymatous in areas of conceptacle production; vegetative portions of thallus endophytic in Jania verrucosa (the only known substrate) but conceptacles produced external to the host; haustoria present, consisting of specialized cells that form cell fusions with cells of host thallus
Thallus without apparent dorsiventral, radial or isobilateral organization; thallus construction diffuse to monomerous, consisting of discrete, branched filaments that become partially consolidated in areas of conceptacle production but collectively lack any regularised internal structure. Endophytic filaments apparently lacking epithallial cells but most conceptacle roof filaments each terminating in an epithallial cell; outermost walls of epithallial cells apparently rounded or flattened but not flared at the corners; cell-elongation characteristics uncertain; cells of adjacent filaments apparently not linked by cell fusions or by secondary pit-connections.
Female gametangia (carpogonia) and carposporophytes developing in uniporate conceptacles; male gametangia (spermatangia) and male conceptacles unknown. Carpogonia terminating 3?celled unbranched filaments that arise from the conceptacle chamber floor. Carposporophytes developing in carpogonial conceptacles after presumed fertilization; mature carposporophytes composed of a central fusion cell and ‘carposporangial chains’ (see comments) of up to four carposporangia .
Tetrasporangia formed in conceptacles on separate plants from gametangia and carposporangia; conceptacles not buried in host. Roofs of tetrasporangial conceptacles multiporate and composed of cells. Tetrasporangia each containing four zonately arranged spores and producing an apical plug that blocks a roof pore before spore release. Bisporangia unknown.
Information contributed by: Wm. J. Woelkerling. The most recent alteration to this page was made on 5 Oct 2010 by M.D. Guiry.
Characters considered diagnostic of Epulo: Epulo is the only known genus of Hapalidiaceae, Subfamily Austrolithoideae with: 1) a largely endophytic thallus composed mainly of unconsolidated filaments except in areas of conceptacle production; 2) diffuse to monomerous thallus construction without any regularised internal vegetative structure; 3) haustoria present, consisting of specialized cells that form cell fusions with cells of the host; and 4) conceptacles produced external to the host.
Parasitism, used by Townsend & Huisman (2004: 289) in their generic diagnosis, refers to a mode of nutrition and thus is a physiological character, not a morphological one. By contrast, the occurrence of haustoria, the morphological character that provides evidence for a parasitic mode of nutrition, is listed above as a diagnostic character.
Townsend & Huisman (2004: 292-293) also suggest that the number of nuclei (one vs. more than one) in vegetative cells that have not undergone fusion is an important generic character, but they did not include this feature in their generic diagnosis. According to Townsend & Huisman (2004: 292) vegetative cells in Epulo are always uninucleate; whereas in Austrolithon (also in the subfamily Austrolithoideae), cells may be uninucleate or multinucleate (Harvey & Woelkerling 1995: 366; Townsend & Huisman 2004: 292 & Table 1). The situation in Boreolithon, the other genus of Austrolithoideae, is unknown, and thus it is difficult at present to fully evaluate the potential generic significance of nuclear number within the Austrolithoideae.
Characters considered diagnostic of higher taxonomic ranks known/presumed to occur in all species of Epulo: 1) calcification in the form of calcite; 2) pit plugs with two cap layers at cytoplasmic faces, the outer cap dome shaped; membrane absent; 3) cell walls impregnated with calcite; 4) gametangia and carposporangia produced within uniporate conceptacles; 5) tetrasporangia/bisporangia possessing zonately arranged spores and produced within conceptacles; 6) tetrasporangial/bisporangial conceptacles possessing multiporate plates or roofs; 7) tetrasporangia/bisporangia producing apical plugs; 8) tetrasporangial/bisporangial conceptacles with multiporate roofs composed of cells; lacking an acellular multiporate plate recessed below a single outer opening; and 9) cells of contiguous vegetative filaments not linked by cell fusions or by secondary pit-connections. Characters 1-2 are considered diagnostic of the Corallinophycidae, 3-5 of the Corallinales, 6-7 of the Hapalidiaceae, and 8-9 of the Austrolithoideae
Generic synonyms: No synonyms of Epulo are known.
Comments: Knowledge of Epulo and the single known species, E. multipedes, is based entirely on the original detailed account (Townsend & Huisman 2004)of the type and only known collection. According to those authors, the extent to which vegetative thallus filaments are calcified is uncertain, but conceptacles definitely are calcified. In terms of growth-form (Woelkerling et al. 1993), plants of Epulo are classed as unconsolidated. The only known host is Jania verrucosa (Corallinaceae, subfamily Corallinoideae).
Epulo is presumed to be parasitic as evidenced by the occurrence of haustoria (specialized cells or extensions of cells that are presumed to absorb nutrients from a host organism). In Epulo, haustoria constitute entire cells that partially fuse with cells of the host. Haustoria have not been recorded to date for the other two currently recognized genera of Austrolithoideae (Austrolithon & Boreolithon), but only a few collections of each are known, and, consequently, the diagnostic value of haustorial occurrence in genera of the Austrolithoideae requires further study. Townsend & Huisman (2004), however, used haustorial occurrence to help delimit Epulo as a genus.
Townsend & Huisman (2004: 292, fig. 17) describe carposporophytes as producing ‘carposporangial chains’ of up to four carposporangia, but such chains do not appear evident in their figure 17, which seems to show short filaments with terminal carposporangia.
Biogeographically, Epulo presently is known only from the type collection, gathered at Long Reef Point, Sydney, New South Wales, Australia.
The lists below of diagnostic characters of Epulo, and of the higher taxa to which it belongs, are derived from data in Townsend & Huisman (2004), Harvey, Broadwater, Woelkerling & Mitrovski (2003), Harvey, Woelkerling & Millar (2003), Le Gall & Saunders (2007), Woelkerling et al. (2008: 282) and/or Le Gall et al. (2009). Diagnostic characters are those that taken together distinguish a taxon from others of the same taxonomic rank (e.g. characters distinguishing Epulo from other genera of the Hapalidiaceae, subfamily Austrolithoideae).
Numbers of names and species: There is only one species or infraspecific name in the database at present, which has been flagged as accepted taxonomically on the basis of the listed literature under the species name. In some instances, opinions on taxonomic validity differ from author to author and users are encouraged to form their own opinion. AlgaeBase is a work in progress and should not be regarded as a definitive source only as a guide to the literature..
Names: ('C' indicates a name that is accepted taxonomically; 'S' a homotypic or heterotypic synonym; 'U' indicates a name of uncertain taxonomic status, but which has been subjected to some verification nomenclaturally; 'P' indicates a preliminary AlgaeBase entry that has not been subjected to any kind of verification. For more information on a species click on it to activate a link to the Species database):
Click here to also show infraspecific names in the list below.
Harvey, A.S., Broadwater, S.T., Woelkerling, W.J. & Mitrovski, P.J. (2003). Choreonema (Corallinales, Rhodophyta): 18S rDNA phylogeny and resurrection of the Hapalidiaceae for the subfamilies Choreonematoideae, Austrolithoideae and Melobesioideae. Journal of Phycology 39: 988-998.
Harvey, A.S. & Woelkerling, W.J. (1995). An account of Austrolithon intumescens gen. et. sp. nov. and Boreolithon van-heurckii (Heydrich) gen. et. comb. nov. (Austrolithoideae subfam. nov., Corallinaceae, Rhodophyta). Phycologia 34: 362-382.
Harvey, A.S., Woelkerling, W. J. & Millar, A.J.K. (2003). An account of the Hapalidiaceae (Corallinales, Rhodophyta) in south-eastern Australia. Australian Systematic Botany 16: 647-698.
Harvey, A.S., Woelkerling, W.J. & Millar, A.J.K. (2009). The genus Amphiroa (Lithophylloideae, Corallinaceae, Rhodophyta) from the temperate coasts of the Australian continent, including the newly described A. klochkovana. Phycologia 48: 258-290.
Le Gall, L. & Saunders, G.W. (2007). A nuclear phylogeny of the Florideophyceae (Rhodophyta) inferred from combined EF2, small subunit and large subunit ribosomal DNA: establishing the new red algal subclass Corallinophycidae. Molecular Phylogenetics and Evolution 43: 1118-1130.
Le Gall, L., Payri, C.E., Bittner, C.E., & Saunders, G.W. (2010). Multigene polygenetic analyses support recognition of the Sporolithales, ord. nov. Molecular Phylogenetics and Evolution 54(1): 302-305.
McNeill, J., Barrie, F.R., Burdet, H.M., Demouline, V., Hawksworth, D.L., Marhold, K., Nicolson, D.H., Prado, J., Silva, P.C., Skog, J.E., Wiersema, J.H. & Turland, N.J. (2006). International Code of Botanical Nomenclature (Vienna Code) adopted by the Seventeenth International Botancial Congress Vienna, Austria, July 2005. pp. [i-iv], v-xviii + 1-568. Liechtenstein: A.R.G. Gantner Verlag.
Townsend, R.A. & Huisman, J.M. (2004). Epulo multipedes gen. et sp. nov. (Corallinaceae, Rhodophyta), a coralline parasite from Australia. Phycologia 43: 288-295.
Woelkerling, W.J., Irvine, L.M. & Harvey, A.S. (1993). Growth-forms in non-geniculate coralline red algae (Corallinales, Rhodophyta). Australian Systematic Botany 6: 277-293.
Woelkerling, W.J., Millar, A.J.K., Harvey, A. & Baba, M. (2008). Recognition of Pachyarthron and Bossiella as distinct genera in the Corallinaceae, subfamily Corallinoideae (Corallinales, Rhodophyta). Phycologia 47: 265-293.
Verification of data
Users are responsible for verifying the accuracy of information before use, as noted on the website Content page.
Some of the descriptions included in AlgaeBase were originally from the unpublished Encyclopedia of Algal Genera, organised in the 1990s by Dr Bruce Parker on behalf of the Phycological Society of America (PSA) and intended to be published in CD format. These AlgaeBase descriptions are now being continually updated, and each current contributor is identified above. The PSA and AlgaeBase warmly acknowledge the generosity of all past and present contributors and particularly the work of Dr Parker.
Descriptions of chrysophyte genera were subsequently published in J. Kristiansen & H.R. Preisig (eds.). 2001. Encyclopedia of Chrysophyte Genera. Bibliotheca Phycologica 110: 1-260.
Created: 03 September 2005 by M.D. Guiry
Linking to this page: http://www.algaebase.org/search/genus/detail/?genus_id=47599
Please cite this record as:
Guiry, M.D. & Guiry, G.M. 2019. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 24 April 2019.